Mold for forming apertures in concrete construction



April 1934- I E. L. CHAMBLISS, JR., ET AL 1,954,788

MOLD FOR FORMING APERTURES IN CONCRETE CONSTRUCTION Filed May 19, 1932Patented Apr. 17, 1934 UNITED STATES PATENT? OFFICE MOLD FOR FORMINGAPERTURES IN CONCRETE CONSTRUCTION Edward L. Chambliss, Jr., and EdgarH. Obernier, St. Louis, Mo.

This invention relates generally to concrete-- construction. Moreparticularly, our invention has reference to an aperture-forming moldand has for its prime object the provision of a simi ple, inexpensivemold that may with facility and convenience be employed for theeconomical and efficient production during the construction of concretefioors, walls, and the like of apertures or openings therein for wires,piping, and other desired purposes.

And with the above and other objects in view, our invention resides inthe novel features of form, construction, arrangement, and combinationof parts hereinafter described and pointed out in the claims.

In the accompanying drawing,

Figure l is a fragmentary sectional view of a mold embodying ourinvention, the shell thereof being shown as disposed and mounted on the20 floor frame-work in preparation for pouring of the concrete;

Figure 2 is a view similar to Figure 1, showing the concrete cast in oron the frame-work for enveloping the mold-shell;

Figure 3 is a generally similar view, showing the frame-work beingstripped from the castconcrete;

Figure 4 illustrates the embedded apertureforming shell being removedfrom the formed aperture; and

Figure 5 illustrates the concrete-work after removal of the shelltherefrom, showing the finished or formed aperture therein.

Referring now more in detail and by reference characters to the drawing,which illustrates a preferred embodiment of our invention, the mold Aincludes a hollow shell or sleeve 1 open at its opposite ends andpreferably, though not necessarily, of circular or tubularcross-section, the wall of the shell or sleeve 1 being also preferablyconstructed of a spirally wound strip 2 of suitable material, aswater-proofed cardboard, fibreboard, sheetmetal, or the like.Preferably, the helically adjacent edges of the strip 2 are seamed oradheringly connected at the spiral parting lines 3, the connection beingeffected suitably for preventing mortar-leakage between the strip edgeswhile permitting parting or separation of the shell-wall at the seams 3.For such purposes, the edges of the strip 2 may be connected by asuitable glue-material, if the shell is made of cardboard or fiber, orby solder if the shell is constructed of sheet-metal. Should, however,the shell 1 be constructed of an otherwise constructed tube of thematerial selected, the wall of the tube may, while not here specificallyshown, be suitably scored or weakened for enabling ready removal thereoffrom the formed opening, and it is to be understood that other methodsof constructing the collapsible or removable shell 1 may be employed aswill best serve the purpose.

Adapted for fiatwise engaging or seating on and over an end of the shell1 for marginally overlapping the side-wall thereof and for providing anend-closure therefor, is a preferably discshaped cover or cap 4constructed preferably of a suitable bendable or collapsible material,such, for instance, as card-board, fibre-board, or the like.

5 designates a fastening or tie-member, which, in the present instance,is preferably in the form of an elongated wire nail, the cover 4 beingsuitably apertured for snugly receiving the shank of the nail 5 with thehead of the nail engaging the outer face of the cover 4 and the shank ofthe nail 5 having a length to extend through and beyond the opposite orlower end of the shell 1, as best seen in Figures 1 and 2.

6 designates a so-called head of disc-shape in the present instance fordisposition within the shell 1 for rimwise snugly engaging the interiorface of the wall thereof, the head 6 being centrally apertured foraccommodating the shank of the nail 5 for axially centering the shell 1thereon and with respect to the work.

In the employment of the mold during'erection of concrete-work, theconventional wooden frame-work or lagging B is built up for the purpose,for instance, of casting a concrete floor C, the center of the openingto be formed in the floor C being indicated on the upper face of thelagging B as by a suitable indentation or the like. The cover 4 and head6 are suitably mounted on the nail 5, and the latter inserted in andthrough the shell 1, the point of the nail 5 being then placed at themark prepared for locating the position of the mold A on the lagging B.

The nail 5 is then driven from above pointwise securingly into theframe-work B for both securing the cover 4 on the shell 1 and the shell1 to the frame-work B, the shell 1 being endwise gripped firmly betweenthe cover 4 and the frame-work B, the head 6 meanwhile taking a positionadjacent the frame-work B for axially centering the shell 1 over, andthereby definitely locating the mold A at, the desired position on theframe work 8.

The concrete for the floor C is then poured or cast on the floor-form B,in which operation the cover 4, being firmly seated on the upper end ofthe shell 1, closes the same against entry of the concrete thereinto,and in like manner the firm bearing of the lower straight end of theshell 1 on the frame-work B prevents leakage of mortar into the moldaround the bottom end thereof, while the engagement of the head 6between the nail 5 and shell 1 not only reinforces the shell 1 againstthe pressure of the hardening concrete, but also effectively preventsdisplacement of the same during the concrete pouring operation.

After the concrete has hardened, the framework B is dropped or strippedin the usual manner, and the nail 5, being firmly fixed in the laggingB, follows the same as it is stripped from the floor C. In suchmovement, the head of the nail 5 is either pulled through the cap 4,permitting the ready removal of the cap, or the cover 4 is caused tocollapse or fold around the head of the nail 5 and to be drawn into andthrough the shell 1, as specifically illustrated in Figure 3. Meanwhilethe head 6 is engaged either by the collapsed cover 4 or the head ofnail 5, and is also withdrawn from the shell 1 by and with theframe-work B as the same is removed from the fioor C, as will also beunderstood from Figure 3.

Most conveniently then from either the top or bottom of the fioor C, theadjacent end of the strip 2 is loosened and grasped by the fingers, as

shown in Figure 4, whereupon, with ease and facility, the strip 2 may bespirally unwound and withdrawn from the opening formed in the floor bythe mold A, the wall of the shell 1 separating readily along the partingline 3, as will be understood, leaving a clear, smooth-walled opening '7in and through the floor C, as shown in Figure 5.

In practice, the mold is particularly adapted for use in concreteconstruction having lagging merely on one side, as in floors and thelike, for forming openings in the fioor for the passage of pipes,conduits, and other similar purposes. However, the mold may for likepurpose be employed in concrete constructions having lagging on opposingsides, as in walls, columns, and the like.

The mold may be cheaply and inexpensively manufactured, is mostconveniently usable, and is exceedingly efiicient in the performance ofits intended functions. The mold, constructed as described, is notsubject to expansion or contraction by atmospheric changes, and hencecracking of the cast concrete is obviated, and the sleeve or shell 1, ifpermitted to remain in the formed opening, functions as a cushion forthe inserted pipes, wires, and the like.

If it is desired to use a sheet-metal form i'n'- stead of thewooden-frame B, the nail 5 may be replaced by an elongated bolt or likefastening element, a suitable aperture being provided in the metal-formfor receiving the bolt, and it will be understood that other changes andmodifications in the form, construction, arrangement, and combination ofthe several parts of the mold and the method of use thereof may be madeand substituted for those herein shown and described without departingfrom the nature and principle of our invention.

Having thus described our invention, what we claim and desire to secureby Letters Patent is,-

1. In a mold for forming an aperture in concrete construction, anopen-end tubular shell of integral formation and uniform diameter forendwise disposition on the construction framework, a rendible disc forloosely fitting fiatwise on and marginally over the upper end of theshell, and an elongated nail for engaging the disc and the frame-workand extending lengthwise through the shell for securing the shellendwise on the frame-work, the disc being tearable for endwise removalof the nail through the lower end of the shell.

2. In a mold for forming an aperture in concrete construction, anopen-end tubular shell of integral formation and uniform diameter forendwise disposition on the construction framework, a cardboard disc forloosely fitting fiatwise on and marginally over the upper end of theshell, and an elongated nail for engaging the disc and the frame-workand extending lengthwise through the shell for securing the shellendwise on the frameework, the disc being collapsible for removalthrough the lower end of the shell.

3. In a mold for forming an aperture in concrete construction, anopen-end tubular shell of integral formation and uniform diameter forendwise disposition on the construction frame-work, a cardboard disc forloosely fitting fiatwise on and marginally over the upper end of theshell, an elongated nail for engaging the disc and the frame-work andextending lengthwise through the shell for securing the shell endwise onthe frame-work, and a second disc fitting removably within and looselyrimwise abutting the inner face of the shell adjacent its lower end foraxially, with respect to the nail, centering the shell on theframe-work, the first disc being collapsible for removal with the nailand second disc through the lower end of the shell.

EDWARD L. CHAMBLISS, JR. EDGAR H. OBERNIER.

